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Development and application of HVOF sprayed spinel protective coating for SOFC interconnects

Research output: Contribution to journalReview ArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)631-639
Number of pages9
JournalJournal of Thermal Spray Technology
Volume22
Issue number5
DOIs
Publication statusPublished - Jun 2013
Publication typeA2 Review article in a scientific journal

Abstract

Protective coatings are needed for metallic interconnects used in solid oxide fuel cell (SOFC) stacks to prevent excessive high-temperature oxidation and evaporation of chromium species. These phenomena affect the lifetime of the stacks by increasing the area-specific resistance (ASR) and poisoning of the cathode. Protective MnCo2O4 and MnCo1.8Fe 0.2O4 coatings were applied on ferritic steel interconnect material (Crofer 22 APU) by high velocity oxy fuel spraying. The substrate-coating systems were tested in long-term exposure tests to investigate their high-temperature oxidation behavior. Additionally, the ASRs were measured at 700 C for 1000 h. Finally, a real coated interconnect was used in a SOFC single-cell stack for 6000 h. Post-mortem analysis was carried out with scanning electron microscopy. The deposited coatings reduced significantly the oxidation of the metal, exhibited low and stable ASR and reduced effectively the migration of chromium.

Keywords

  • ASR, HVOF spraying, interconnect, protective coating, SOFC, spinel, stack testing